I'm trying to understand the closest_point function in qgis. For that, I created a polygon layer with two features, and through the Geometry Generator I intend to find the closest point between those two.
This is the expression I'm using, but it is not working:
closest_point(geometry (get_feature_by_id('closest', 1)), geometry(get_feature_by_id ('closest', 2)))
Can someone help me to find out why?
Your expression should work well, but you have geometry errors in your layer: you have multipart geometries with just one part. That's what the Check Geometries tool found.
To solve the problem: run Menu Vector / Geometry tools / Multipart to singleparts - in the resulting layer, both your original as well as the following expression should work:
closest_point(
geometry (get_feature_by_id (@layer, 1)),
geometry (get_feature_by_id (@layer, 2))
)
@layer refers to the current layer.
Check Geometries tool. It was the inverse: you had two separate features, but somehow QGIS consiedered them to be multipart, but they consisted both of just one part, thus it was inconsistent.